ABSTRACT: Contributions of regional scale climate change research to the management of climate risks were explored at a meeting of researchers, policymakers, and practitioners in June 2007 (convened by the Task Group on Data and Scenario Support for Impact and Climate Analysis of the Intergovernmental Panel on Climate Change). Although existing knowledge is already being used to inform a wide variety of decisions in multiple contexts, there remain significant knowledge gaps that hamper effective climate-risk management, particularly at the interfaces of different spatial and temporal scales of analysis and cross-system interactions. In this Introduction we synthesize discussions of such knowledge gaps, and highlight recommendations for user-oriented research that produces and communicates information that is credible, defensible, and actionable for climate-risk management.